Anyone who has carried out a discovery exercise will be well aware of the pitfalls it can contain. This is especially true where potentially relevant documents are stored on a variety of electronic devices. In a recent Supreme Court decision, Ms Justice Laffoy urged caution when relying on search terms to identify all the relevant documents pertaining to a case.

Details of the case

  • This litigation concerned the termination by the Defendant of a Volkswagen dealership contract it entered into with the Plaintiff. As part of the Plaintiff’s claim for breach of contract, he sought discovery of certain categories of document from Volkswagen. He brought a motion to strike out Volkswagen’s Defence and Counterclaim on the grounds that its discovery was incomplete. In particular, the Plaintiff sought an order compelling Volkswagen to identify the search terms it used when retrieving relevant documents from its IT systems and an order allowing his own IT expert access to the Volkswagen IT systems to carry out his own review.
  • Volkswagen admitted that its initial attempt to comply with the discovery request was insufficient and when the plaintiff initially complained about the inadequacy of the discovery provided, a more thorough trawl was carried out. This comprehensive search included a review of all central systems, laptops, back up media, shared devices, personal devices, portable devices and USB keys. It confirmed that key words were devised in conjunction with its lawyers which resulted in the retrieval of approximately 60,000 documents.
  • The Plaintiff sought an order requiring Volkswagon to furnish a list of the key words it had used and argued that unless the key words were disclosed, the methodology adopted by Volkswagen could not be scrutisined and the court could not be satisfied with the adequacy of the discovery.


  • Laffoy J noted the observations of Clarke J in Thema International Fund v HSBC Institutional Trust Services (Ireland) [2012] 3 IR 528 that the cost of discovery in complex litigation can typically amount to 50% of the total cost of litigation and that the Courts need a balancing exercise. The Court endorsed Clarke J’s view of search terms, that where a party is conducting discovery by using search terms, a balancing exercise is required. The search terms cannot be too wide as to cast the net over too many irrelevant documents or too narrow so as to risk excluding other relevant documents. The Court was satisfied that as long as a party acts bona fide in relation to search terms it should not face criticism or adverse consequences if it should transpire that some documents slipped through the net.
  • Laffoy J cautioned that any search of documents by keywords has the potential for getting things  wrong.

However, in this case, the court was satisfied with the comprehensive and documented trawl that Volkswagen carried out of its IT systems and refused the Plaintiff’s request for the search terms to be revealed.


This case highlights the caution that should be used when carrying out a discovery exercise using search terms. They can be a valuable tool in narrowing a large number of electronic documents. However, overreliance on them can lead to certain documents being omitted.

Pat O’Leary v Volkswagen Group Ireland Limited [2015] IESC 35